This study is intended to provide a simple technique for inducing intervertebral disc degeneration in Rhesus monkeys. The technique involves the application of stress fixtures between adjacent transverse processes. We intend to monitor pressure, volume, and morphological changes in the disc and its adnexae, with a view to being able to predict the degree of degeneration attained. We also intend to examine the alterations in the physical properties of the disc, including elasticity, resistance to nuclear extrusion, and shear strength. Physiological changes in metabolite processing and exchange will also be monitored via the use of radioactive tracer materials.